Apatura metis Freyer, 1829

(Fig. 9)

Apatura metis Freyer, 1829: 61, pl. 67(1) [Type locality: “Süd-Ungarn”]; Fixsen, 1887: 292 ( ilia var.); Lee, 1982: 73; Masui and Inomata, 1990: 6; Lee, 1992: 4; Korshunov and Gorbunov, 1995: 73; Tuzov et al., 2000: 14; Lee, 2005: 27.

Apatura ilia var. bunea Herrich-Schäffer, [1845]: 45, pl. 36(161–163) [Type locality: Caucasus]; Fixsen, 1887: 292 ( ilia ab.) (first record from Korea); Okamoto, 1924: 88 ( ilia subsp.); Nakayama, 1932: 379 ( ilia subsp.); Mori et al., 1934: 33 ( ilia subsp.); Kishida and Nakamura, 1936: 514 ( ilia subsp.); Seok, 1939b: 52 ( ilia subsp.); Kim and Mi, 1956: 395 ( ilia f.); Seok, 1973: 76 ( ilia f.).

Apatura substituta Butler, 1873: 159 [Type locality: northern China]; Leech, 1893: 162 ( ilia var.); Moore, [1896]: 7 ( Potamis).

Apatura ilia: Leech, 1887: 417; Shin, 1975: 45; Takakura, 1981: 4 (nec Denis and Schiffermüller, 1775).

Apatura ilia f. gertraudis Stichel, 1908: 163 [Type locality: “S. Russland ”]; Nakayama, 1932: 379 ( ilia getrandis [sic]); Kishida and Nakamura, 1936: 515 ( ilia getrandis [sic]); Seok, 1939b: 54 ( ilia subsp.); Seok, 1942: 87; Seok and Umitatsu, 1942: 186; Kim and Mi, 1956: 395; Seok, 1973: 80; Lee, 1978: 40 ( metis f.).

Apatura ilia f. substituta: Stichel, 1908: 163; Nire, 1918: 94 ( ilia subsp.); Doi, 1919: 122 ( ilia subsp.); Okamoto, 1924: 88 ( ilia subsp.); Doi, 1928: 49 ( ilia subsp.); Doi, 1931: 45 ( ilia subsp.); Nakayama, 1932: 379 ( ilia subsp.); Seok, 1934: 718 ( ilia subsp.); Mori et al., 1934: 33 ( ilia subsp.); Seok, 1936: 62 ( ilia subsp.); Kishida and Nakamura, 1936: 516 ( ilia subsp.); Seok, 1939a: 178 ( ilia subsp.); Seok, 1939b: 56 ( ilia subsp.); Seok, 1942: 87; Seok and Umitatsu, 1942: 186; Kim and Mi, 1956: 396 (substitua [sic]); Murayama, 1963: 43, 45 ( ilia subsp.); Seok, 1973: 86; Lee, 1978: 40 ( metis f.); Okano, 1998: 6 ( metis subsp.).

Apatura ilia ab. mikuni Wileman, 1910: 93 [Type locality: Mikuni, Province of Bungo, Japan]; Nire, 1918: 95 ( ilia subsp.); Doi, 1931: 45 ( ilia subsp.); Nakayama, 1932: 379 ( ilia subsp.); Seok, 1934: 717 ( ilia subsp.); Mori et al., 1934: 33 ( ilia subsp.); Kishida and Nakamura, 1936: 515 ( ilia subsp.); Shirôzu, 1938: 2 ( ilia subsp.).

Apatura ilia heijona Matsumura, 1928: 198 [Type locality: Corea]; Bollow, 1930: 194; Kishida and Nakamura, 1936: 515; Inomata, 1982: xvii ( metis subsp.); Masui and Inomata, 1990: 7, 9 ( metis subsp.).

Apatura ilia metis: Doi, 1928: 49, 50; Maruda, 1929: 127; Nakayama, 1932: 379; Kishida and Nakamura, 1936: 515.

Apatura ilia subsp.: Mori et al., 1934: 33.

Apatura mikuni: Seok, 1936: 62 .

Apatura ilia gracilis Bang-Haas, 1936: 346 [Type locality: “Charbin”, “Mandschurei”]; Masui and Inomata, 1990: 7, 9 ( metis subsp.).

Subspecies. The Korean populations are considered to belong to subsp. substituta as are the populations in northern China (type locality) and Far Eastern Russia. The Japanese populations are considered to belong to subsp. mikuni . Some authors have treated the populations in Korea and the Amur and Ussuri regions as subsp. heijona (cf. Tuzov et al. 2000) or as the nominal subspecies (cf. Lee 1992). However, heijona is believed to be a variation within the range of subsp. substituta .

Adult. Active from early June to mid July, late July to late August and early September to early October (two or three broods in central and southern Korea, but only one brood in high altitude areas). Both sexes often perch on the leaves, branches or stalks of their food trees. When sitting on a stalk, they frequently position themselves with their heads toward the ground. They also puddle and are attracted to carrion and fermenting fluids, and neither sex visits flowers. In the afternoon, males engage in hilltopping on trees standing on hills or lowlands.

Larval host plants. Recorded hosts include Salix gracilistyla Miq., Salix babylonica L., Salix caprea L., etc. of the Salicaceae (Joo et al. 1997) .

Life cycle. Not documented for the Korean populations. Usually the 3rd instar larvae hibernate on diverging points of two branches or in furrows of trunks of the food plants.

Distribution. Korea (including some adjacent islands of Incheon and Gyeonggi-do, but not on Jejudo Is.), northeastern China, Far Eastern Russia, Japan, southeastern Europe, southwestern Siberia and Kazakhstan.

Remarks. Apatura ilia and Apatura metis are often confused with each other because of their extreme similarity and confusing infraspecific variations. Moreover, intermediate forms between the two species occur at high frequency (perhaps as high as 10%; personal observation) in many areas where the two species are sympatric. For these reasons, these two species have long been treated as a single species in Korea as well as in many other countries of East Asia (cf. Seok 1939b). The Korean Apatura metis was treated as independent from Apatura ilia for the first time by Lee (1978).

Intermediate forms are thought to be natural hybrids between these two allied species. This has led to disputes over the taxonomic status of A. ilia and A. metis based on differing species criteria―some argue that occasional hybrids do not negate species status, while others argue that the currently observed rate of hybridization requires subspecific treatment of the forms (strict biological species concept), especially because of their morphological similarity. Here, A. ilia and A. metis are treated as valid species because they are often sympatric, they sometimes share the same plants, and they fly during somewhat different periods.